We propose to acquire a recently developed, dually configured confocal microscope (the LSM 5 Duo, Zeiss)[unreadable] to support the research of a group of 9 NIH-funded investigators at the University of Maryland School of[unreadable] Medicine. These investigators each have immediate need for high-speed, multi-color fluorescence confocal[unreadable] imaging during photoactivation, photobleaching, or long-distance Z motion. No equipment with the required[unreadable] capabilities exists on campus. The Zeiss Duo combines the well-established, high-resolution optical[unreadable] sectioning capabilities of the LSM 510 with the high-speed imaging capabilities of the more recent LSM[unreadable] 5Live. The two, independent beam-steering systems of the Duo create the synergistic capacity for[unreadable] simultaneous region-of-interest photomanipulation during rapid image acquisition. The Major Users each[unreadable] confirmed that the capabilities of the Duo directly and uniquely well meet their requirements. The new[unreadable] instrument will be incorporated into the long-standing Confocal Core Facility at the University, where it will[unreadable] replace an LSM410 that was purchased in 1994 and is neither suitable nor reliable for the live-cell[unreadable] experiments that now occupy the large majority of time on the confocal microscopes in the Facility. After[unreadable] evaluating possible system configurations from the major vendors, the Facility?s oversight committee also[unreadable] agreed that the Duo presented the only configuration that would meet the increasing demand for highspeed,[unreadable] live-cell imaging while providing consistent access to a high-resolution point-scanning confocal.[unreadable] Accordingly, institutional support is very strong at the Dean?s level and also spread widely among many[unreadable] Departments with extensive NIH-supported research. The presence of the Duo in the Confocal Core[unreadable] Facility would directly and strongly benefit the research of the Major Users; more broadly, it would add an[unreadable] important new capability for advancing the NIH-sponsored research of the many other investigators on[unreadable] campus studying biological processes in living cells and systems.